1. Field of the Invention
The present invention relates to a camera accessory shoe and to an electronic flash device which can be detachably mounted to the camera accessory shoe.
2. Description of the Prior Art
Conventional cameras, such as the single lens reflex camera (SLR), are typically provided on the top with an accessory shoe of a type such as shown in FIG. 16 such that electronic flash devices can be mounted by sliding the mounting member of said device into the shoe. In such an application, improper contact connections when mounting the electronic flash device on the camera have been prevented by forming the contacts on the electronic flash device as a peak-like shape and adequately arranging the positions of the contacts. In such cases, however, when the number of contacts is to be increased, a broad area for the contact array is necessary in the direction perpendicular to the insertion direction of the electronic flash device if improper connections during mounting are to be avoided, and this makes design extremely difficult.
At the same time, many cameras of the type which mount an electronic flash device without using an accessory shoe such as shown in FIG. 16 are also known. On cameras of this type, a contact block for the electronic flash device is concentrated in a small space, and the electronic flash device is mounted by pushing contacts of the flash device onto a flash mount surface of the camera and engaging or screwing the flash device in place. Specifically, because the flash device is not mounted by sliding the flash device across the mounting surface, improper contact connections during mounting do not occur. However, the construction at a flash mounting portion is complex, and mounting tends to be cumbersome.
As cameras have become more functionally advanced, it has become desirable to alter the configuration of the slide mount accessory shoe for a number of reasons, including the need for an increased number of contacts in the electronic flash to camera connection, for the shape of the accessory shoe to be elongated in the direction of an optical axis when used for electronic flash devices provided with an auxiliary light source for automatic focusing so that the optical axes of the camera and flash device are precisely aligned, and for the ability to effectively utilize the cramped space on the camera.
Arraying the contacts in a series in the direction of flash device insertion has been one possible way to change the shape of the accessory shoe and to satisfy the conditions of the above requirements, but in this case problems such as do not occur with the conventional accessory shoe as illustrated in FIG. 16 may occur, specifically, improper contact connections may transitionally occur during flash mounting.
If the camera circuitry and the flash circuitry are improperly connected, the camera circuitry and/or the flash circuitry may function improperly and in extreme cases the circuitry of either device may be impaired. Furthermore, it may also happen that the circuitry misoperates during flash mounting or removal, causing the flash to go off and thus surprising the photographer.